Casting under pressure



Dec. 9, 1930. s. JUNGHANS' 1,784,600

CASTING UNDER PRESSURE Filed July 24, 1928 Invarian- Siegfried, dunzdavzs Patented Dec. 9, 1930 UNITED STATES SIEGFRIED JUNGHANS, OF BADEN,GERMANY CASTING UNDER PRESSURE Application filed July 24, 1928, SerialNo. 295,056, and in Germany December 20,.1927.

My invention relates to a new method of casting under pressure and animproved mold for the production of solid or'hollow bodies of variousforms by casting under pressure.

' In the art of casting under pressure as hitherto practised,particularly in cases where the melting point of the metal or alloy tobe used lies above 7 00 (1., the molds wear away verysoon so that only arelatively small number of castings can be produced. successively in oneand the same mold. This serious disadvantage is mainly due to the factthat the hot molten metal or alloy is to be thrown or squirted at a highpressure from the inlet opening or nozzle towards the inner surfaces ofthe mold and consequently the said inner surfaces of the molds aremechanically affected to a high degree the more so as the said surfacesare subjected to an intense cooling action immediately upon the castingoperation. Obviously the surfaces cannot withstand for a permanency or agreater length of time such heavy attacks both of the mechanicalpressure and of the considerable differences of temperature so that finefissures and cracks will soon form in the surfaces and such cracks willincrease and grow larger at each subsequent casting operation wherebythe casting ultimately will be given a bad appearance or will beunserviceable in some cases or require at least an expensive subsequentor finishing treatment.

It will be seen that in many cases the expense incurred to overcome theexplained disadvantage considerably oifsets the advantage of the methodof casting under pressure and renders the latter uneconomical.

The chief object of my invention is to remedy this defect and toovercome thestated disadvantage in a simple and economical manner. lViththis purpose in view I overcome the excessive strain to which the innersurfaces of the mold are subjected in the previous art due to theenormous heat and the high pressure of the molten metal, by pre upon theventing the latter from strikin inner surfaces of .themold imme iately,that is by divertin the same from its rectilinear path or direction anddistributing the jet of of without any cooling or preheating means,

molten metal over a larger area in a most possibly uniform manner sothat the molten metal will be introduced into the mold at a reducedpressure and at a lower temperature.

Obviously the method can be carried out 55 in practice in quite a.variety of different ways. Thus the diversion or deviation and thedistribution of the jet of molten metal may be brought about in variousdifferent ways by inserting a suitable obstruction or even, if'desired,by simply causing the molten metal to take a tortuous path in the mold.At any rate, it is essential that the current or jet of molten metalwill be diverted in a manner that no metal coming direct from themelting oven, will strike immediately the inner surfaces of the mold. Inother words, the jet of molten metal rushingat a considerable pressureinto the mold is influenced in a manner that the molten metal will enterthe space or chamber of the mold, properly speaking, at a reduceduniform pressure and at a rather decreased uniform temperature. It goes.without saying that my improved method is applicable both in connectionwith molds having a single molding space or chamher only and inconnection with molds havmg a plurality of spaces or chambers.

With the above recited object in view, reference is had to the followingspecification 30 and drawings in which there is exhibited one example orembodiment of a mold designed for carrying out the invention but whichis in no way intended as a limitation upon the scope of theappendedclaims as it is to be clearly understood that'variations andmodifications which fairly fall within the scope of said claims, may beresorted to when found expedient.

In the accompanying drawings forming a part of this specification andshowing, for purposes of exemplification, a mold having a plurality ofmolding chambers:

Figure .1 illustrates the construction there- 5 and Figure 2 illustratesa modification equipped with cooling or preheating means.

In both cases shown the jet of molten metal is diverted by adistributing member 12 and being cooled or subjected to a '0respectively, provided in the path the jet of molten metal is caused totake, and located across or transversely to the inner charging orifice.The jet of molten metal impinges, on its way through the orifice 1) intothe mold f of 7, respectively upon the distributing member so as to bedlverted and directed thereby towards and into thelater al moldingchambers 1, 2 etc. At the same time the pressure of the molten metalwhile thus being uniformly spread, will be reduced due to the impact onthe distributing member and the distribution accomplished thereby. Thefact that those surfaces of the distributing member which are directlystruck by the jet of molten metal, are damaged by cracking, is of noaccount as regards the castings to be produced, since the portion of thecasting formed in the vicinity of the distributing surfaces forms partof the dead head which in any case is but Waste to be returned to themelting furnace. I

Moreover the distributing member may be constructed and arranged so asto be capable of being readily exchanged when injured and worn, for anew one, so that the mold will be adaptable for use for ya comparativelygreat length of time, preferably by providing suitable channels in thewall of the mold, as shown in Figure 2, the distributing member may beimproved so as to be capable of preliminary heating.

From the foregoing, it is believed, that the advantages and novelfeatures of my invention will be readily understood and, therefore,further detail description is deemed unnecessary. I do not of coursedesire to be limited to any articular way of carrying out the improvedmethod or to the exact details of construction and arrangement shown anddescribed as modifications are no doubt possible as hereinbefore alreadyintimated, which would still come within the scope of the invention andI aim in the appended claims to embrace all modifications falling fairlywithin the scope of my invention.

What I claim is 2- 1. A multi-part pressure casting mold, comprising apair of mold sections, one section having a charging channel therein andbranch channels in the sections terminating at one end into a moldchamber and the other end into the charging channel at ri ht ."anglesthereof; and a distributingmem er in the other mold section opgosite thecharging channel and having a epression adjacent thereto in eachcharging channel forming shock and connecting surfaces for the purposeof reducing the speed, pressure and temperature of the jet of moltenmetal to prevent injury to the mold chamber.

2, A multl-part Pressure casting mold, comprising a pair 0 moldsections, one section having a charging channel therein and branchchannels in the sections terminating at one end into a mold chamber andthe other end into the charging channel at right angles thereof; adistributing member in the other mold section opposite the chargingchannel and having -a depression adjacent thereto .in each chargingchannel forming shock and connecting surfaces for the purpose ofreducing the speed, pressure and temperature of the jet of molten metalto prevent injury to the mold chamber; and means for cooling and heatingsaid shock and connecting surfaces of the distributing member.

3. A multi-part pressure casting mold, comprising a pair of moldsections, one section having a charging channel therein and branchchannels in the sections terminating at one end into a mold chamber andthe other end into the charging channel at right angles thereof; adistributing member inthe other mold section opposite the chargingchannel and having a depression adjacent thereto in each chargingchannel forming shock and connecting surfaces for the purpose ofreducing the speed, pressure and temperature of the jet of molten metalto prevent injury to the mold chamber; hollow chambers adjacent saidshock and connecting surfaces and concentric with said distributingmember and said chargingchannel; and channels in the wall of the moldterminating in said hollow chambers for heating and cooling said hollowchambers and said-shock and connecting surfaces.

In testimony'whereof, I afiix my signature.

SIEGFRIED JUNGHANS.

